Content Delivery Services (CDS) are applications that enable or enhance the quality of experience of the end-to-end transfer of data over a network. For example, Content Delivery Services include Security Processing, Virus Scanning, Policy Enforcers, Load Balancing, Network Address Translation processing and Streaming Content Caches. In the past the content delivery services have been layered on top of the services provided on an end system. However, executing the CDS on the end system adversely impacts the ability of the end system to perform its intended function, which reduces the performance and increases the cost of the end systems themselves. To overcome these problems, the provision of Content Delivery Services has migrated from the end user systems to the network edge.
However, network edge architecture is designed to optimize the performance potential of the communication medium, and therefore is not always the best architecture for providing high quality Content Delivery Services. Typically Content Delivery Services are provided at the edge by appliances that are either pure software or hardware assisted software processes. While software processing enables a larger number of individual appliance offerings to be made to the user, it does not provide the optimum per appliance performance, and is also inefficient in terms of power, area and cost. Hardware assisted architectures typically include one or more customized ASICs coupled to the network device via an external bus architecture, such as the Peripheral Computer Interconnet (PCI) bus. The customized ASICs are designed such to provide optimal per appliance performance. However, if multiple appliances are provided in the network offering, bottlenecks quickly arise at the PCI interface. In addition, the hardware assisted architectures are expensive, and inefficient in terms of power, area and cost.
It would be desirable to identify a network architecture which would support the offering of various Content Delivery Services appliances while enabling desired power, area, cost and bandwidth constraints to be met.